As a personal adviser to William Hague, Lord Howell of Guildford helps the Foreign Secretary promote Britain’s interests abroad. The father-in-law of George Osborne has, however, accepted a post in which he will be paid handsomely to champion a foreign country.

Mandrake can disclose that David Howell has signed up as an adviser to the Kuwait Investment Office. He had previously been a consultant to the oil-rich kingdom, but gave up the work before becoming a Foreign Office minister in 2010. He stepped down as a minister in last September’s reshuffle, but remained as an adviser.

The Advisory Committee on Business Appointments, which counsels former ministers on their employment in the two years after leaving office, says, “Lord Howell sought advice on resuming a part-time appointment as an adviser to the Kuwait Investment Office”, which “manages funds on behalf of the State of Kuwait”.

It says Frances Osborne’s father “will meet managers intermittently to advise on international investment strategy”.

The committee has approved the appointment, “on the understanding that he would not draw on any privileged information from his time in government”.

Last month, questions were raised about another of Howell’s business activities. He is a con­sul­tant to a Ja­panese high-speed train firm ex­pected to ten­der when the con­tro­ver­sial HS2 rail line is built. The peer, who was Margaret Thatcher’s transport secretary, is being paid as a “European consultant” to JR Central, which could be a bidder for multi-million-pound contracts connected to HS2.